1. Field of the Invention
The present invention relates to ad servers and ad syndication systems used to display advertisements on web pages.
2. Description of the Related Art
Various types of ad server systems exist for displaying targeted advertisements on web pages. One type of system allows business entities (advertisers) to associate their respective ads with specific keywords, which may include phrases. When a user submits a search query to an Internet search engine, the ad or ads associated with the keyword or keywords entered by the user are displayed on the resulting search results page—typically under a heading such as “sponsored links” or “sponsored results.” The display position of each such ad relative to other ads, and the amount paid by the corresponding advertiser if the ad is clicked on by a user, is typically dictated by a keyword bid amount specified by the advertiser. Typically, the ads of each advertiser are displayed on a variety of different independent web sites through a process known generally as syndication.
Another type of ad server and syndication system operates by selecting ads to display on relatively static web pages by performing content-based analyses of such pages. For example, Google's AdSense program allows web site operators to configure selected pages of their respective web sites to display or “host” ads served by a remote ad server. To select appropriate ads to display on a given page, a crawler program analyzes the textual content of the page, and attempts to match the page's content to relevant ads.
A significant problem with existing ad server and syndication systems is that they do not provide an effective mechanism for allowing web site operators to control the types of ads displayed on their respective web sites. As a result, some web site operators are deterred from displaying or “hosting” syndicated ads on their sites. For instance, online merchants are commonly unwilling to host sponsored link type ads due to the risk that these ads will lure away potential customers. Although some systems permit creation of a URL filter to block ads for certain businesses, this approach does not inhibit the display of ads for web sites and businesses that are unknown to the operator of the ad-hosting web site.